Code Samples: flush

Showing posts with label flush. Show all posts

Wednesday, September 28, 2022

How To Use Gradients in Flutter with BoxDecoration and GradientAppBar

Color gradients take a starting color and position and ending color and position. Then it performs a transition between the colors. With consideration for color theory, they can make an application more visually interesting than a plain design.




import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter Gradient Example'),
      ),
      body: Center(
        child: Container(
          decoration: BoxDecoration(
              gradient: LinearGradient(
                begin: Alignment.topRight,
                end: Alignment.bottomLeft,
                colors: [
                  Colors.blue,
                  Colors.red,
                  Colors.green,
                  Colors.yellow
                ],
              )
          ),
          child: Center(
            child: Text(
              'Hello Gradient!',
              style: TextStyle(
                fontSize: 48.0,
                fontWeight: FontWeight.bold,
                color: Colors.white,
              ),
            ),
          ),
        ),
      ),
    );
  }
}









Compile your code and have it run in an emulator: 

This creates a linear gradient that starts at 0.0 of the way down the screen with blue then red then green and last yellow.

Wednesday, August 3, 2016

Grails track hibernate transaction begin, flush, commit and rollback status

Package: org.springframework.orm.hibernate4

Class: HibernateTransactionManager

Wednesday, October 23, 2013

Duplicated records/data persistence/flush session error with Grails in synchronized method

Consider some of cases:

When domain fails to save data because of duplicate record.
When an unsaved domain belongsTo a domain, then showing: 'save the transient instance before flushing'.

Then - Domain.save(flush:true) - didn't work because of threading.
Here is example of my thread creation:

Thread.start {
    Domain.withTransaction {
         // Doing stuff and calling synchronization method to write data to DB
    }
}

Fix was found here: Grails, GPars and data persistence
I replaced "Domain.withTransaction" with "Domain.withNewSession":

Thread.start {
    Domain.withNewSession {
         // Doing stuff and calling synchronization method to write data to DB
    }
}

and save(flush:true) start writing into mySQL. Since data is written to mySQL, findBy... start returning proper results and therefore I application doesn't try to create duplicated record anymore. Issue solved!

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